1. Field of the Invention
The invention relates to a method for selectively effecting the washing of production zone fractures, the treatment of such fractures by injection with chemicals, such as acidic solutions, and, if required, the swabbing or flow testing of low flow wells after such treatment, utilizing a single tubular tool string which is run into the well only once to accomplish any one or all of the three operations.
2. Description of the Prior Art
After the casing of a subterranean well has been perforated in a production zone, it is often desirable to effect the washing or treatment of the adjacent perforations with water, acid, or chemicals or a series of washing or treating operations. If the well has very low flow characteristics, it may also be necessary to conduct a swabbing operation on the well to determine the rate of flow of oil from the treated perforations.
If the well has sufficient formation pressure, it may be necessary to isolate the producing zone and flow test the zone. While these individual operations have been known and practiced in the past, it has been necessary to make more than one round trip of appropriate tool strings into the well for accomplishing more than one of the aforementioned perforation treatment operations when using a packing element type washing or injecting tool to isolate short sections of the perforations.